Photolithographic printing art



Dec. 4, 1956 M A. MATTARE Pao'ror.I'rHoGRAPHIc:V PRINTING Am' Filed June 8, 1951 my.; 4. l Mark A. Mazza@ Byjv Y Flowing We l G ease'v Lake TTORNEYJ United States Patent() i 2,172,942 y t PHoToLiTHoGRAPHIC PRINTING RT Mark A. Mattare, Alde, Va. Application June 3,1951, serial No. 230,560

s Claims.` (c1. 41-46) This invention relates to an improved method of applying various characters such as a word, legend, symbol, numeral, indicia or pattern to a negative for instance such as used in the lithographic printing art. The invention is more particularly applicable to the production of maps, charts and the like, and permits corrections and additions to be made directly on the negative plate without the use of photography which has been the common practice heretofore in making such additions or corrections to the master negative.

In the preparation of maps, for example, it is conventional practice to prepare a master copy showing the towns, rivers, lakes, roads and contours, and whereinthe various4 names and legends are cut-out from opaque printed adhesive/sheets and gluedv to the master copy at the proper location. The finished master copy is then photographed and a `negative plate prepared therefrom for use in making offset or straight printing reproductions of the master copy. A proof is pulled on Vthe proving press and this is sent to the proof reader for final checking before a sensitized metal printing plate is made for they press. Invariably, the proof reader finds changes and corrections to be made which usually involves the addition or changing of words, symbols or patterns on the master copy. A

When changes are required to be made on the master copy as shown on the proof, theltype compositor sets up the names, symbols or the like legends which are desired to be added to the mastercopy. Then a print or prints are pulled and sent to the photographer. After this is done, a specially prepared negative is made. For example, a wet print negative, containing the names or symbols to be added, is coated with a suitable stripping solution and, after drying, one or more applications of a oollodion coating solution is broadcast over the negative.r Thereafter, the negative'is placed in acetic acid bath which permits the ready removal of the lmcontaining the names, symbols or patterns which are to be placed on the wet Vnegative print. The desired names or symbols are cut out of the film. by the use of a sharp knife and transferred to the Wet negative, the lm portions being placed in a window or cleared-out space on the negative.

This prior method of making additions to the master negative, as described, is a very tedious as well as eX- pensive method and requires the use of photographic equipment and necessitates working `with a wet negative print. The method of the present invention, however, entirely eliminates the. need of photography in making such changes on the master negative plate or lm and either a wet or dry negative plate or film may be changed or corrected. Furthermore, in utilizing the improved method of this invention, such additions and changes can be made in a much shorter time and at substantially less expense to the lithographer. r

The principal object of the present invention is to greatly simplifytheV method, ofvmaking changes, corrections or additions on a wet or dry master negative plate or lm.

Another object of the invention is to provide a method of placing selected characters, as aforementioned, on a negative, such as commonly mounted on glass or a like transparent surface, without requiring the use of photography and making of a photographic negative of the characters to be applied to the master negative.

Still another object of the invention is to provide an inexpensive and simple method of making changes and corrections on a negative plate so that the work of highly skilled artisans is not required as well as eliminating the need for preparing an auxiliary photographic negative Vof the characters or legends to be added to the master negative.

Briefly, the method of the present invention comprises the following steps:

(l) The printing of the various names, symbols, numbers or other legends to be used on a transparent ,cellulose xanthate or viscose sheet, such as cellophane, the transparent sheet being printed on both sides. i

(2) Exposing the printed form in step (l) to a sensitized aluminum plate from which arprint is pulled using ink which results in a negative print of the aforementioned names, symbols, etc.

(3) Coating the negative'print thus'formed with adhesive wax, and cutting out the desired name or symbol to be inserted on the master negative and placing the cutout legend directly on the negative plate, being'simply pressed against a window opening scratched or otherwise made on thenegative at the desired location.

(4) After touching up any space left aroundthe cutout insertion on the master negative plate with opaque material, the corrected master negative is now ready to be printed to sensitized aluminum and the resultant plate transferred to the press.

Where the correction in the master negative plate, for example, involves a change in a pattern or printed lines, Vand which patterns or the like are commonly printed on a transparent flexible regenerated cellulose sheet such as Zipotone, the cut-out portion of the cellulose sheet having the desired pattern is merely coated with the adhesive wax and applied directly to a window made in the master negative plate as described above in the case of a printed name or symbol.

The improved and simplied method of applying various characters to a lithographie negative plate is further illustrated in the accompanying drawing in which,

Figure 1 is a fragmentary view illustrating a portion various legends for selective use in making additions on the master negative;

Figure 3 is a negative print of a portion of the printed cellulose sheet shown in Figure 2 and illustrated on an enlarged scale;

Figure 4 is a similar fragmentary portion of the negative print illustrated in Figure 3 after applying a coating of adhesive wax thereto and before application ofthe same to the back of a glass plate; Y

Figure 5 is a fragmentary View illustrating the removal of a legend portionrfrom a negative print, such as shown in Figure 4, and illustrating the use of tweezers for separating the cut-out legend from the glass backing sheet;

Figure 6 is a fragmentary detail view in enlarged scale showing a portion of the master negative plate as'disposedon a glass sheet, and illustrating the manner of i A.therein and adhesively secured in place; and

l a printed map. prepared in accordance with this invention and showing a legend 12 and a lake pattern 14 which have been added directly to a kphotolithographic master negative 1 5 which is arranged on a glass plate 16. The steps required for adding. the legend Flowing Well is graphically illustrated iny Figures 2 through 6, and comprises pr'mting o f the legend 12 together with other legends or characters as desired on both sides of a thin, transparent, regenerated, cellulose sheet 1S such as cellulose xanthate. This print is then formed into a negative print by exposing the same to a sensitized aluminum plate, the resultant negative being rolled up on a metal plate with regular cellophane ink tov form a negative print film 2i). The negative print lm 20 preferably has a thickness of approximately one-thousandth of an inch.

After the thus prepared negative print iilrn 2t) is dry as by placing the same on a drying rack or blotter until the ink is dr'y, an adhesive wax coating 22 is applied thereto.

Where oiset printingis to be used, the adhesive coating i is appliedon the printing face and where straight printing is to be employed, the adhesive coating is applied on the opposite face as will be understood.

In the drawing, the lithographie master negative 15 is arranged on the glass backing 16 for oifset printing and, accordingly, the negative film 20 is coated on its printed face with adhesive as indicated at 22 on the drawing. The wax adhesive composition which forms no part of this invention, lgenerally consists of a suitable mixture of rened beeswax and latex rubber. The proportion of ingredients is such that the adhesive is made to hold the cut-Outs by means of pressure only, the coating being preferably applied evenly over the surface of theV negative print at a temperature between about 90 and 110 C. After coating the negative print lm 2l) carrying the desired characters with the adhesive wax coating, the print is applied to the back of a glass sheet 24 as illustrated in Figure 5 so as to conveniently hold the negative print material whereby the same can be readily cut out for transfer to the master negative plate.

When it is desired to correct the lithographie negative plate 15 solas tov add a legend for example as indicated by the reference character'12, an instrument 25 having a sharpvr edged blade is used Vtocut out the legend from the negative print lm as shown at 26 in Figure 5. A corner of theV cut-out legend is conveniently raised by inserting the edge orc the blade of the instrument 25 thereunder and grasping theraised corner by means of tweezers as illustrated at 28. In this manner, the cutout printed negative legend 261which is to be transferred to the master negative is removedfrom the glass backing sheet 24. Thereafter, the cut-out negative legend 26 is then transferred direetly'toa scratchedv out window 30 formed iu the lithographie master negativeplate 15, the cut-.out being securedr in place by. pressing the same down firmly against the glass surface in the window of the master negative. The adhesive wax on the face of the legend portion serves to hold the same securely to the negative glass-plate.

As shown in Figure 6, the window 39 in the negative 15 isV suitably scratched or cut out by using the sharpened edge blade portion of the instrument 25. After applying the legend in the window, the open space 32-left around the legend 2 6 is filled with negative opaque. The thus corrected master negative plate 15, as illustrated in Figure 7, is then ready for printing to sensitized aluminum and installation of the resultant plate on the printing press.

Where a particular pattern or printed lines are desired to be placed on the master negative plate, such as commonly used to illustrate a lake, and wherein a printed pattern of the desired illustration is available on a transparent sheet such as Zipotone, as aforementioned, the adhesive wax may be applied to the printed pattern and a cut-out portion of the desired size may, as illustrated at 34 in Figure 7, be merely pressed into place directly on the lithographic master negative plate 15. The wax adhesive applied thereto, as illustrated, on a turned-up portion in Figure 7 functions to rmly hold the same in place on the master negative-plate.

It will, accordingly, be seen that by utilizing the present invention, various legends, words, numerals, patterns or character references may be readily applied directly to the master negative and without the use of photography and in a simple and` easy manner.

Although the invention has beenv illustrated and described in connection with the preparation of a master negative on a glass plate for'the reproduction of printed maps, it will be understood that the invention isV not lim ited to this particular use. The invention, for example, may be advantageously employed for making additions and corrections on similar negatives or their equivalents, the invention being limited only insofar as defined by the scope of the hereinafter appended-claims.

What is claimedV is:

l. A method of making an addition to a master negativeefrom which a lithographie printing plate is to be produced, said methodr comprising providing a transparent master negative plate with indicia thereon and which indicia requires changes, ink printing a positive legend of said changes -on a transparent strip, exposing the positive printed transparent strip'to a sensitized plate Vto obtain a printing plate, pulling an ink impression in negative form on transparent material from the printing plate, forming a transparent area in the master negative plate at the position requiring said changes, and securing the Vtransparent material carrying the pulled negative impression in the transparentY area of the master negative plate.

2. The invention according to claim 1, wherein the positive legendA is printed on both sides of the transparentl strip.

3. The invention according to claim l with the additional-step of masking with opaque coating material any uncovered portions of the transparent area showing around the applied'material carrying the pulled negative impression.

4. The invention according to. claim 1 wherein said sensitized plate is aluminum.

5. A method of making an addition to a master negative from which a lithographie printing plate is to be produced, said method comprising providing. a transparent master negative plate with indicia thereon and which indicia requires changes, ink printing a positive legend of said changes on a transparent strip, exposing the positive printed transparent strip to a sensitized plate to obtain a printing plate, pulling an ink impression in negative form on transparent material from the printing plate, applying'an adhesive wax coating to the transparent material carrying the pulled negative impression, securing the last mentioned transparent material by the said adhesive wax to a glass plate and cutting outa portion of the transparent material.V carrying the desired pulled negative impression, forming a transparent area in the master negative plate at the position requiring said changes, and adhesively securing'thesaid/cut out portion Y of transparent material carrying the desired pulled nega- (Referenceson: following page) Y References Cited in the le of this patent UNITED STATES PATENTS Cornwall Oct. 9, 1917 Newton Aug. 7, 1928 Jannenga Nov. 19, 1929 Sutclilfe July 12, 1932 Huebner June 13, 1933 Heintz May 7, 1940 Donaldson May 29, 1945 10 

